Spurred perhaps by national outrage over the 2017 "Unite the Right" riot in Charlottesville, hate groups are going underground.

They are stepping up the use of propaganda to distribute their messages of bigotry in lieu of organizing public events.

The Anti-Defamation League today released a study showing extremist groups are increasing the use of racist, anti-Semitic, Islamophobic and anti-LGBTQ leaflets, banners, posters, stickers and flyers to spread ideas of intolerance throughout a community and create fear among members of targeted groups.

The organization found a 182 percent surge to 1,187 propaganda incidents last year.

Ku Klux Klan groups registered 97 incidents, up 20 percent from 2017, in which members left fliers on doorsteps or driveways. The highest activity was in California, New York, Florida, Texas, Illinois and Virginia.

Annual Propaganda Distribution Counts

Alt-right groups opted mainly for banners in high-visibility places like highway overpasses. The Texas-based Patriot Front placed 21 of the 32 banner instances in 2018. It also distributed hateful material at multiple synagogues, an African-American church and placed "Fake News Don’t Buy It" stickers on newspaper offices.

The use of propaganda allows hate groups to shield the identity of individual members while limiting risks of arrests, bad press and public backlash. It's also a cost-effective tool. Social media amplifies the propaganda messaging.

"Hate groups were emboldened in 2018, but their increase in hate leafleting indicates that most of their members understand this is a fringe activity and are unwilling to risk greater public exposure or arrest."

As the use of propaganda rises, the number of pre-announced rallies has declined.

Pre-announced rallies that were held last year suffered from low attendance and heavy counter-protests.

The ADL reports the National Socialist Movement sponsored the biggest pre-announced white supremacist event in 2018.

It attracted only 40 people to Newnan, GA, to mark the birthday of Adolph Hitler, the 2017 rally drew 125.